How does one PROPERLY go about designing a 100% Solar System?

[KenTechno]

I'm new to this site, so Happy New Year to all!

Planning on updating my knowledge of Solar Systems this year, it's come a long way in the past 10 years.

1) Emergency back-up Solar Plant with Battery Back-up (non-Grid connected) - 2.5kWH/Day Max (x5 days Battery Reserve for Snow/Blizzards/Snow Storms, other random natural events or power shorts). In a real emergency, we would ration, and put Thinking to scale-up gradually here in terms of Battery System.
2) Max needed working presumptions: 12kWh/Day Winter to 18-20kWh/Day Peak summer (Grid vs Hybrid [latter is Grid Connectable]).

Question:
What are some good additional ways to make an assessment to size Solar Systems?
1) For emergency (want to take care of this first).
2) As new funds become available. Second task, is to tackle the full house system (most likely heavily experienced professional installer), for daily use (Hybrid- meaning off-grid direct use, with the option of Grid connecting with a licensed electrician).

Any suggestions for measuring Daytime vs 24hr use of Key High Amp/Volt appliances (Microwave, A/C, Electric Toaster Oven, and 25-40AMP Electricals like Dryer, Electrical Range, etc.?). I've looked at the Annual Usage (2yrs averages by Month and year). Looks like a 5-8% variance between years for me, even adjusted for Monthly average temp. Using a Kill-A-Watt, plug in, looked at what I thought were the big energy consumers (Refrigerator 1.3kWh/Day, freezer 0.8kWh/Day, couple of rooms (excluding lighting) 0.8kWh/Day, stereo/TV systems ).

Background:
So I've been looking at tons available information the past few months, following the devastation of 2012's Hurricane Sandy, in the North East. We all our lost power, and anyone lucky enough have or buy a fuel generator, couldn't get to a working gas pump. The lines for fuel were so long than the fuel stations ran out of fuel, before 1/2 of them even got to the station, so the cost/benefit is a moot issue in an emergency.

[Naptown]

If you are going to do this the only way this makes sense is with a hybrid system. You are cycling your batteries much less under this scenario and they will last much longer. You will also have a chance for a ROI by doing this but it will be a long time coming.
At 12 KWH per day winter you are looking at a huge battery system. If you were strictly off grid it would require a 60KW battery bank. If you go hybrid you could use a deeper discharge of say 40-50% Daily DOD. This will reduce the battery size but at the expense of battery life. It depends on how often and for how long the power is on battery. but expect about 1/2 the cycles or less at this discharge rate.
The next thing is to look carefully at the loads that will be applied to the batteries. The rated AH of a bank will decrease when discharged at a rate greater than capacity/20 which is the standard discharge rate. Google Peukerts law there is some good information out there on this topic.
I would shy away from AC coupled systems on a hybrid and do a straight hybrid such as the xantres xw series. These will provide the simplest way to install and maintain the system.
Lastly you will need a generator anyway. You need to get away from the gasoline and move to Natural gas or propane.

[Sunking]

Any suggestions for measuring Daytime vs 24hr use of Key High Amp/Volt appliances (Microwave, A/C, Electric Toaster Oven, and 25-40AMP Electricals like Dryer, Electrical Range, etc.?).

You cannot run those things off solar. Well you can if you have more money than you know what to do with and like throwing it away.

For example to run a electric dryer is a 3000 watt item At 48 volts would require a minimum 48 volt, 600 AH, 1500 pound $6000 battery. It would only be capable of running a dryer 2 hours per day or enough for about 2 loads. It would also require a 3000 watt solar panel and 60 amp charge controller to maintain it. No you want to add all that other high power stuff. You are easily looking at over $60,000 of equipment with $30,000 of that in batteries you have to replace every few years. You will end up paying 10 times more for electricity the rest of your life.

No other way to say it other than that is just ignorant to go off grid if you do not have to.

[bonaire]

Is this a reaction to the recent Sandy storm?

Consider a good natural gas or propane generator.

[Mike90250]

In the case of an Ice storm or hurricane, that shreds the electrical distribution system, you must consider what would happen to a $20,000 rooftop of glass solar panels. If you have a garden shed you can store a 3-5Kw generator, and fuel for a week, you are way ahead of the $20k of PV expense. In the case of an ice storm, you will not have sun, and the PV system is dead. If the weather and grid conditions are bad, longer then you have fuel for, the generator is dead! So, what to do?

I say a small 1-2KW inverter generator that will run your fridge and a fan, for 6 hours a day, a single, cheap 12V marine battery, a 120VAC battery charger, and a string of 12V led lights. If you want, add a 200w PV panel & charge controller. You can keep your beer cold, and have lights on all night to annoy the neighbors ! Or you can go all elaborate and spend $25K in gear, and use it twice in your lifetime.

Just bringing up alternatives to consider.

[Naptown]

I own a portable generator that gets used for events like this. I have never had a problem with fuel. The reason is I don't wait till after the storm to try to get it. I use about 3 gallons of gas a day in my 5000W unit. I also have 6- 5 gallon gas cans that get filled just before the storm hits. For the most part these storms are predicted so there is time before the storm hits to prepare. Waiting till after is a recipe to be in the dark. The only time I had trouble was during the Derecho of a few years ago as this was not predicted. Cost me a grand total of $700.

[KenTechno]

Thanks for the Great ideas & Tips! Playing with the Puekert Constants diff Batts

If you are going to do this the only way this makes sense is with a hybrid system. You are cycling your batteries much less under this scenario and they will last much longer. You will also have a chance for a ROI by doing this but it will be a long time coming.
At 12 KWH per day winter you are looking at a huge battery system. If you were strictly off grid it would require a 60KW battery bank. If you go hybrid you could use a deeper discharge of say 40-50% Daily DOD. This will reduce the battery size but at the expense of battery life. It depends on how often and for how long the power is on battery. but expect about 1/2 the cycles or less at this discharge rate.
The next thing is to look carefully at the loads that will be applied to the batteries. The rated AH of a bank will decrease when discharged at a rate greater than capacity/20 which is the standard discharge rate. Google Peukerts law there is some good information out there on this topic.
I would shy away from AC coupled systems on a hybrid and do a straight hybrid such as the xantres xw series. These will provide the simplest way to install and maintain the system.
Lastly you will need a generator anyway. You need to get away from the gasoline and move to Natural gas or propane.

Great ideas & info! Been tinkering with numbers for the Puekert Constant and various Battery Amps. Was focusing on "Green/near green solutions" with nearly unlimited cheap fuel access - basically the disruptive Sun PV, Solar heat, Wind, and Decomposition gases, with low noise and smog emissions, I find them more challenging.

I'm temporarily ignoring the ROI for PVs, more of an expensive learning curve (as I expect PV will be one of 3 Emergency Systems for Heating/Cooling & electricity). Definitely going for a Generator (recalling the gas crisis in the mid-70s, the general audience should definitely consider a cheap $300-500. Would definitely suffice for keeping the PV Batts well below 50% DOD, so managing a DOD of 20-25% might be more reasonable) vs. I've been considering H2 Electrical generator/turbine or H2 Fuel Cells (more below).

Solar H20 Heating Panels running about $350-500 a piece is one of the optional heating sources. Cheaper 24/14 Day alternative was a compost/hose water heater at $100. Generates well over 200 gallons of heated water for a good sized stack bringing water temp to a peak of 150 F (enough to kill Bacteria & Listeria as well), just have to turn the compost every 10-14 days though, testing a better alternative later. Except for the manual labor, provides 3+ solutions (heated water, garden compost/compost tea/seedling bed heat, and waste recycling).

Generator - Agreed!
Goals here are Viable Bulk Safe Storage, Replacement Fuel/Accessibility, 24/7 access:

Generator would pare very nicely with your Xantrex XM series+genex controller. Gas is easiest, cheapest, & quickest to implement. So, a generator is definitely high on the list considering using a non-consumable fuel generator, maybe Hydrogen, at $1.40/Gallon Gas equivalent vs. Methane, BioAlcohol, or Propane - need to look at the BTU or Joules output vs. storage ability). If they can get H2 safe in cars, bordering upon a 8,000 hour fuel cell lifespan using a Class IV (10,000 PSI-20L should last quite a while), looks viable long term. Regarding emergency fuel/field sourcing, out of curiosity last month I tested an Alkaline H2 production using "Soda bottle, screws, wire, 9 Volt, Alkaline Water" - the micro bubbles came pouring out, so stopped immediately - easy enough to collect, under controlled conditions, actually saw an overpriced Teaching Toy for $100, doing the same thing, running a small model car). Also, reviewed what appears to be a relatively easy $25 5HP engine conversion to Hydrogen Combustion engine (4%-75% of H2 plus air was enough to get running here), far smaller and efficient than any green solution I've seen so far, and actually cheapest so far AND generates steam heat for a turbine generator. Also, looks like the commercial H2 Fuel Cell electrical generators are running about $49/kWh (<$500/ for a 8-10KwH, back-up H2 system would be very viable) - the estimate was based on an 80kW Powerplant for electical vehicles similar to the Honda FCV-R, released last month. Recycles distilled water. The fuel cells concept seem very delicate - looks like a challenge balancing energy production with proper Distilled H20 (too dry/too wet=powerloss), and heat sinking away. So, going with the electrical H2 turbine plan for now.

Thanks again! - Ken

[KenTechno]

Thanks, was assessing the kWH for all appliances, before powering feasibility

You cannot run those things off solar. Well you can if you have more money than you know what to do with and like throwing it away.

For example to run a electric dryer is a 3000 watt item At 48 volts would require a minimum 48 volt, 600 AH, 1500 pound $6000 battery. It would only be capable of running a dryer 2 hours per day or enough for about 2 loads. It would also require a 3000 watt solar panel and 60 amp charge controller to maintain it. No you want to add all that other high power stuff. You are easily looking at over $60,000 of equipment with $30,000 of that in batteries you have to replace every few years. You will end up paying 10 times more for electricity the rest of your life.

No other way to say it other than that is just ignorant to go off grid if you do not have to.

Thanks SunKing,
The dryer is a 40+ year old Maytag and probably a Black hole for energy consumption as you suggest. Been passed along by the previous home owner, been waiting for the thing to die - might eventually scavenge parts for the side projects, since most everything appears to still work. Right now a low level priority, but a challenge to see if I can get it to run with the H2 electrical generator/turbine. Might serve as a good dump load/heater for future Wind Turbines as well - we get either Sun or Wind (give or take Snow or Rain on the mix), so the power just needs to be harvested and with a properly sized and integrated system less than 1/3 needs to be stored - undecided at this stage if H2 can be a viable low cost storage option for peaks in energy production & Lead-Acids seem to be the default for up to moderate current draws, when sized properly. Seems to me we're at another stage of disruptive improvements to green energy - turns the grid to a secondary option and poor utility management creates a greater percentage of blackouts and price hikes. Finding it harder to justify new home construction at $300-450/Sq ft vs a couple thousand for PVs or Wind Turbines-either are insurable and either can be destroyed.

In re-reviewing the alternatives to grid, I've learned that every year 3 million people in the US lose power from hours, days, weeks, or in parts of NYC for months without power now. Many parts of New Orleans remain uninhabitable after a Decade - lacking infrastructure, Can't fathom what it's like living in tornado alley. So, on-grid becomes an overnight surprise. Until you've lost power for a few days, it's easy to forget that electricity, gasoline engines, cars, and computers only came into existence in the last 30-100 years. People still did laundry year round back then, with some interesting hand operated and hand crank "laundry machines". A dryer is basically a drum that turns in a box, with a heat source - PVs can turn that Drum and a Solar heater can provide drying heat - I'm happy to wait a couple hours for my clothes to dry. I hung my clothes to dry after Sandy and it took about 2-3 hours to dry in the dry winter air, I already heat the house so effectively near 0 additional energy cost and no clunking dryer

[Sunking]

Stay far away from H2 systems/ Nothing energy or earth friendly about them. If you think battery power is expensive and inefficient with 50% best case. H2 is down less than 5%. Horrible waste of resources.

[KenTechno]

Is this a reaction to the recent Sandy storm?

Consider a good natural gas or propane generator.

Hi Bonaire! Thanks for the suggestions. Been through a number of power outages, every time, saying this too shall pass.... Sandy was the 3rd "100 year" storm in a decade here with multiple day power loss, so more of a final wake-up call to bite the bullet and have a nearly automated system in place. My thinking is if critical items are on and being used daily - less to worry about when the warnings come though. Either I could wonder if I have enough fuel, batteries and electricity and will the generator start to make it past the next storm or bite the bullet and put a comfortable plan in place to get past a potential crisis. If I'm already functional off-grid, losing Grid power becomes a minor inconvenience, rather than planning how to keep a refrigerator full of food cold, stay warm, clean, and fed - so 2.5kWh/Day for me makes the difference between being uncomfortable vs. dealing with mass media panic.

Anything beyond the 2.5kWh/day is just another level of safety margin, redundancy, and minimizing the effects of a power outage. So 5xDays of Battery power (presumes no sun/snow blockout for 5 days-highly unlikely) would need 12.5kWh of stored energy (at 50% DOD, that is 2000Ahr of Battery Storage). My thinking now, is if I integrate wind/H2/Propane generator(s) - worst case scenario, I can probably cut down that number to 1000-800 AHr and still have a 40-50% DOD buffer, thereby keeping the batteries alive for at least a 1000 cycles). As I understand the Peukert curve, planning for 10-20% DOD daily use ensures even higher cycling times upto 2000+/maybe giving 5-10 years service life - I'm still going to work on the assumption that my first set of batts will die off prematurely, just in case. I think this happens because of both learning curve for maintenance and a lack of battery conditioning with placed in-service. I'll only know for sure with experience this year though.

Stay warm!
- Ken

[KenTechno]

Almost forgot about tha Beer!

In the case of an Ice storm or hurricane, that shreds the electrical distribution system, you must consider what would happen to a $20,000 rooftop of glass solar panels. If you have a garden shed you can store a 3-5Kw generator, and fuel for a week, you are way ahead of the $20k of PV expense. In the case of an ice storm, you will not have sun, and the PV system is dead. If the weather and grid conditions are bad, longer then you have fuel for, the generator is dead! So, what to do?

I say a small 1-2KW inverter generator that will run your fridge and a fan, for 6 hours a day, a single, cheap 12V marine battery, a 120VAC battery charger, and a string of 12V led lights. If you want, add a 200w PV panel & charge controller. You can keep your beer cold, and have lights on all night to annoy the neighbors ! Or you can go all elaborate and spend $25K in gear, and use it twice in your lifetime.

Just bringing up alternatives to consider.

Thanks Mike for the reminder - gotta have some good cold beer while flashing megawatts of LED lights! I think the Xantrex suggested earlier by Naptown, has a nice auto Genset feature communicating with the programmable Charge controller, so I wouldn't even have to bother turning the fuel generators on/off, thereby conserving fuel/preventing overcharge. I'll check, but I think the newer panels can survive 5200Pa of impact - otherwise I'll have to build them a storm shelter too

The 3kW of Panels (I have an Insolation of about 3 hrs) would run $4-5K - I would think except for golf ball sized hail, a near/direct Lightening strike, or large object striking the roof, the mounting brackets and most of the wiring would be intact. Good warning for those in tornado alley...Fortunately, I don't live in a tornado/twister zone, although they do pass through every 10-years of so. Roof panels would be 20 feet high.

[KenTechno]

Great Generator as 1st or 2nd string back-up!

I own a portable generator that gets used for events like this. I have never had a problem with fuel. The reason is I don't wait till after the storm to try to get it. I use about 3 gallons of gas a day in my 5000W unit. I also have 6- 5 gallon gas cans that get filled just before the storm hits. For the most part these storms are predicted so there is time before the storm hits to prepare. Waiting till after is a recipe to be in the dark. The only time I had trouble was during the Derecho of a few years ago as this was not predicted. Cost me a grand total of $700.

Greatly appreciate the suggestions from everyone here!

Did you leave the generator on all day? Or do you have the auto-starting Genset Controller (The Xantrex XW series you suggested, sounds like it automatically turns the generator on/Off when Batts hit a Default or Factory Genset thresholds or user programmed limits). Didn't realize I could get a 3rd party to turn on/off generators - guessing the Generator would either need a battery start and an add to trigger the for the ignition task. I'll have to double check the manual online before ordering.

[bonaire]

You can use a battery plus generator together without solar. It can cycle the generator on and off and you are not burning gas the whole time. Some Chevy volt owners do this with their car during an outage and can run a 1000 to 1200 watt inverter off the car using occasional runs of the gas engine. It puts stress on the AGM battery but the primary battery of 16kWH is fine when used that way. Down the road, EVs will be see for outages in this way. The technique is called v2h. Vehicle to home. V2h would not use the 12V battery but use the high voltage battery directly. Some activity with that now in Japan.

[KenTechno]

Aew we referring to the same Product?

Stay far away from H2 systems/ Nothing energy or earth friendly about them. If you think battery power is expensive and inefficient with 50% best case. H2 is down less than 5%. Horrible waste of resources.

I was thinking either waste H2 Gas collection or via electrolytic conversion. Hydride tank storage, and using a $25 conversion of a rebuilt 5 HP Gas Low compression engine ($250). $250 Hydride tank The value is in reducing battery Bank storage and managing evening Wind turbine output, instead of load dumping, right after the Solar cells charge the batts. Total cost plus time input of $550 - H2 gas production would be negligible. Looks like I can run either Gas or H2 into the engine, but through a different manifold and electronic timing shift.

Also, listing of few dozen H2 Auto/bus fill-Stations coming on line-Mostly private, for city bus lines & Car companies. Bulk are in California at present time.

http://www.fuelcells.org/wp-content/uploads/2012/02/h2fuelingstations-US.pdf

[KenTechno]

Cool stuff!

You can use a battery plus generator together without solar. It can cycle the generator on and off and you are not burning gas the whole time. Some Chevy volt owners do this with their car during an outage and can run a 1000 to 1200 watt inverter off the car using occasional runs of the gas engine. It puts stress on the AGM battery but the primary battery of 16kWH is fine when used that way. Down the road, EVs will be see for outages in this way. The technique is called v2h. Vehicle to home. V2h would not use the 12V battery but use the high voltage battery directly. Some activity with that now in Japan.

Agreed that a generator makes for a great Portable & emergent uses system - especially for topping off batteries & High Amp appliances.

Cool stuff, but using a $14K+ Car & Li-Ion battery as a battery bank?!? Sounds like asking for an expensive problem - ones on lease actually track usage patterns.